<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .btn-wrapper {
            position: relative;
            display: inline-block;
            margin: 50px;
        }
        .btn {
            padding: 12px 20px;
            font-size: 16px;
            background-color: #007bff;
            color: white;
            border: none;
            border-radius: 6px;
            cursor: pointer;
        }
        .badge {
            position: absolute;
            top: 0;
            right: 0;
            transform: translate(50%, -50%);
            width: 12px;
            height: 12px;
            background-color: red;
            border-radius: 50%;
            box-shadow: 0 0 4px rgba(0, 0, 0, .3);
        }
    </style>
</head>
<body>
    <div class="btn-wrapper">
        <button class="btn">消息中心</button>
        <span class="badge"></span>
    </div>
</body>
</html>